In my U.S. Pat. No. 4,920,291 entitled "Magnetic Thrust Bearing with High Modulation Capability," I disclosed and claimed a unique construction enabling the placement of a magnetic flux carrying lamination in the stator of a magnetic thrust bearing. As is understood in the art, the purpose of the lamination is to minimize eddy currents caused by modulation of the magnetic flux. This application is directed to another unique construction for solving the same general problem; namely, construction of an axial magnetic force actuator having a flux carrying lamination in the rotor as well as the stator. As explained in U.S. Pat. No. 4,180,296, the rotor cannot be made of laminated material because the mechanical strength of the rotor would be too weak. In U.S. Pat. No. 4,353,602, a magnetic thrust bearing is disclosed in which the problem of eddy currents in the rotor is simply ignored. The invention disclosed herein is related to my invention disclosed in U.S. application Ser. No. 385,798, filed Jul. 26, 1989 entitled "Radial Magnetic Bearing."
It is known in the art to construct stators for magnetic thrust bearings with radially disposed E-shaped or U-shaped laminated assemblies consisting of a plurality of sheets (laminae). The sheets are stacked in milled radial slots. In this structure, the sheets themselves are not tapered since to do so would be impractical. This means that the milled slots must have parallel and nonradial side walls and limited circumferential length.